By Priya Ranganathan | Illustration by Asmita Sapre Ranganathan

Listen along to an audio version of this story HERE

How many of you have heard of underwater forests teeming with life? Well, let me introduce you to the most colourful and diverse forests our world has ever seen – coral reefs. 

Most of us grow up thinking that coral is a type of plant because it grows out of the seafloor. But coral is actually classified as part of the animal kingdom. Each individual coral is made up of hundreds of tiny animals known as polyps. These polyps have a tiny stomach (or mouth, depending on its mood), which is surrounded by tentacles. They use their tentacles to pull small passing animals into their mouth and also as a defense mechanism. During the day, they use this mouth to swallow their prey, and at night, waste particles are released into the ocean from this same opening. Strange, isn’t it? 

Two blue-cheek butterflyfishes swimming together in a coral reef (Free public domain CC0 photo)

Coral reefs are not just made up of these coral polyps, but also of thousands of fish, sea anemones, and starfish. From the surface, the ocean looks like an expanse of blue, never changing colour as you progress deeper and deeper. Yet coral reefs are brilliantly coloured in hues of reds and oranges and yellows and purples and pinks. The fishes found here are equally brightly coloured so as to blend in with the surrounding coral. Camouflage is one of the oldest methods of avoiding hungry bigger fish in the ocean! 

Corals require specific conditions to survive and grow, making them some of the most delicate creatures on the planet. They grow best in shallow open clear water with exposure to direct sunlight and warm water temperatures of 23-25 degrees Celsius. When a coral dies, its exoskeleton (the colourful part of the coral that we see when we scuba dive) cements together with millions of other coral skeletons, forming the massive reef structures that we see in nature documentaries. In India, coral reefs can be found in the Gulf of Kutch (the world’s northernmost reefs), Palk Bay, the Gulf of Mannar, and surrounding the various island systems of the country. A 320 km-long barrier reef can be sighted near the Andaman and Nicobar Islands, while 95 km of reef have been documented in the Gulf of Mannar, off the coast of southern Tamil Nadu. 

The Bay of Bengal has fewer coral reefs than the Arabian Sea or the open Indian ocean around the Lakshadweep, Andaman, and Nicobar islands. For one, heavy sediment washing into the ocean from the many east-flowing rivers like the Ganga, the Brahmaputra, the Godavari, the Krishna, and the Kaveri makes the water too silty for coral growth. Also, monsoon rains and high density of people living on the coastline around these deltas makes for limited coral reefs. Just like other natural habitats, coral reefs grow best in calm, undisturbed stretches. 

Coral Woman – a short film that focuses on the destruction of coral reefs in the Gulf of Mannar

But coral reefs, like other natural landscapes, are not safe from harm. One major threat is climate change. As sea temperatures warm, corals undergo a process called bleaching, where they slowly die due to acidification and become white. Have you ever seen photographs of ghostly white coral reefs? Well, those are dead reefs, bleached by rising ocean temperatures. But another human threat is coral mining. In both India and Sri Lanka, coral mining is a common destructive activity, where local men swim down to coral reefs and break off large chunks of coral. This coral is then crushed and used to create cement for building houses and other infrastructure. A documentary called Coral Women looked at coral reefs in the Gulf of Mannar and showed how thousands of corals have been mined and used to make cement, leading to parched reefs and huge gaps where life used to brim under the ocean. People assume coral reefs are lifeless…in truth, it is our interference that saps them of life. 

The National Institute of Oceanography reports that coral mining for construction has destroyed most of the reefs around India. Yet in many parts of coastal India, reef ecotourism brings in a lot of money. For example, hundreds of people go to islands for vacations and scuba dive in reefs to see the colourful coral and brilliant fishes in all shapes and sizes. If corals disappear, so will the livelihoods of the many people who rely on tourism for their daily bread and butter. 

Coral reefs attract divers and tourists to their colourful depths (Image from

Corals live a quiet life and face an even quieter death, but it is now up to us to recognize that they are living creatures who face extinction just as much as any tiger or elephant. With our efforts to raise awareness about coral reefs and the dangers they face, we will be able to bring them back to their colourful glory and preserve them for children of the future to learn about and admire. 

About the Author:

Priya Ranganathan is a wetland ecologist and geologist by training who works in the wild Western Ghats. When she isn’t out wading through swamp forests, she can be found scribbling away in her notebook or practicing Bharatanatyam. Check out her website ‘On Life and Wildlife.

About the Artist:

Asmita Sapre Ranganathan is a doctor, Sanskrit teacher, artist, poet, and writer from Mumbai. She enjoys wearing her many hats and especially enjoys illustrating for children’s books and magazines.